In the future, a mobile communications system will provide a higher data transmission rate and wider service coverage. To reduce a coverage hole and improve service experience of an edge user, more low power nodes (LPN, Low Power Node) are deployed in a heterogeneous cellular network (that is, a heterogeneous network, also called a Hetnet scenario). In a heterogeneous network, by using a radio access technology, a UE may access not only a macro base station, but also any low power access node in a network. In this case, network coverage is extended, and quality of service (QoS, Quality of Service) of a user is ensured. A low power access node is called a low power node for short in the following.
In an LTE (Long Term Evolution, Long Term Evolution) network, for cell reselection in IDLE (idle) mode, time evaluation is performed for the cell reselection based on a Treselection (called a first-cell reselection time parameter) broadcast by a serving base station. If a value of the Treselection is not 0, a user equipment needs to complete the cell reselection within a set Treselection time segment; if the value of the Treselection is 0 or not configured, the user equipment needs to complete the cell reselection within a set Tevaluate time segment (called a first-cell evaluation time parameter), where the Tevaluate is an integral multiple of a DRX (discontinuous reception, Discontinuous Reception) period configured by a network entity. Refer to Table 1, in which Tevaluates are listed, where a unit of time is second (s).
TABLE 1Tevaluate [s]DRX Period Length [s](Multiple of a DRX Period)0.325.12 (16)0.645.12 (8) 1.286.4 (5)2.567.68 (3) 
However, in a heterogeneous network scenario, a network broadcasts only one reselection time value, such as a value of the Treselection, and therefore the following cases may be caused:
Case 1: If the value of the Treselection configured by the network is relatively large, and when a user equipment (UE, User Equipment) moves from a macro cell (Macro cell) to a low power node cell (such as a pico cell, where a pico is one type of low power node), because of a relatively long Treselection time, a user equipment fails to reselect a pico cell in time, and the user equipment may well encounter a radio link failure; or the pico cell may cause relatively strong interference to the UE, so that the UE in IDLE mode fails to receive paging (paging) information from the original macro cell normally.
Case 2: If the value of the Treselection configured by the network is relatively small, and when a UE moves between edges of two macro cells, because of the relatively small Treselection, the UE performs ping-pong cell reselection. This causes frequent reselection of the UE in IDLE mode, so that power-saving performance cannot be well implemented.
Case 3: If the value of the Treselection configured by the network is 0 or not configured, the UE performs cell reselection according to the Tevaluate in Table 1. It can be seen that the evaluation time is at least over 5 s, and for a macrocell-picocell (Macro-pico) scenario, the evaluation time is a relatively long evaluation time. Like case 1, this may cause a radio link failure and a failure in receiving paging (paging) information from a macro cell. As can be seen from the above case analysis, an original time evaluation solution of cell reselection for a macro cell cannot be applied to a heterogeneous network any longer, because it may cause problems such as a link failure, a failure in receiving paging information, and ping-pong reselection.